The present invention relates to encoding and/or decoding of spatial information of a multi-channel audio signal. Recently, various coding techniques and methods for digital audio signals have been developed, and various products associated therewith have also been produced.
However, when a multi-channel audio signal is downmixed in the form of a mono or stereo audio signal, there may be a problem of sound level loss of the audio signal. In particular, a coded signal still exhibits a sound level loss phenomenon even after core codec encoding thereof because the coded signal has a limited size, for example, 16 bits. Such a sound level loss phenomenon of the audio signal affects the output characteristics of the audio signal, and causes a degradation in sound quality.